Expansible drum liner



Nov. 2, 1965 F. A. CONNELL EXPANSIBLE DRUM LINER Filed April 5, 1963omgmw United States Patent 3,215,307 EXPANSIBLE DRUM LINER Frank A.Connell, Wilmington, Del., assignor, by mesne assignments, to The GreifBros. Cooperage Corporation, Delaware, Ohio Filed Apr. 5, 1963, Ser. No.270,915 2 Claims. (Cl. 220-63) This invention relates to containers andmore particularly to an improved drum liner.

It has been a common practice for many years to ship bulk liquids suchas fuel oil, tar and other petroleum products in drums or barrels,generally those having 55 gallon capacity. With the advent of postwarchemical development, a much wider range of liquids of both organic andinorganic derivation began to be shipped in barrels. In cases where theprospective barrel contents would damage the barrel or be contaminatedby the barrel it has been realized that some inert lining means must beprovided in the barrel to separate the liquid contained in the barrelfrom the barrel itself. In addition, most fiber board drums, havinggrown in popularity as substitutes for metallic drums, require some typeof liquid-proof liner.

Two different modes of providing the necessary lining have becomeestablished in the art. The first entails applying an adherent coatingmaterial to a barrel interior prior to or during the assembly of thebarrel. One of the primary disadvantages of the coating method is thatleaks often develop through thin spots in the coating, especially at thejoints between the barrel ends and side wall. Additionally, when thebarrels are reclaimed after a period of use, it is difiicult andsometimes impossible to remove the adherent coating for replacement.

The other lining technique in use employs a separate liner for thebarrel. In the past these separate liners have been composed ofliquid-proofed paper, coated foil, heat welded plastic or the like.These have not met with great acceptance because they generally will notwithstand Interstate Commerce Commission standard drop tests thatbarrels must pass before being used in interstate commerce.Additionally, because of their collapsibility, these liners are usuallynot susceptible to use in tighthead drums, which are preferred byshippers and users. Therefore, these prior art liners had to be used inopen head drums, i.e., drums in which the bot tom is secured by crimpingor welding and the top is secured in place by use of a metal ringsecured by a bolt or locking lever. Experience has shown that open headdrums not only will generally not withstand being dropped from a heightof four feet when filled with water (the standard ICC drop test), butalso are more expensive than comparable tight-head drums because theyrequire a ring and ring retainer as noted above.

Another difiiculty arising from the use of prior art liners is that,while standard in gallonage, barrels or drums vary slightly in heightand Width. Therefore, liners of a single size made to fit all drums of aparticular gallon size will not conform to the interior of barrels oflarge diameter and, having room to move about within the associateddrum, a liner of this type will be subject to vibration induced failureduring shipment.

These paper, foil and plastic linings also are susceptible to seamfailure during use with ensuing damage to both barrels and barrelcontents and sometimes danger to lives and property.

Accordingly, it is an object of the present invention to provide aseamless barrel liner capable of safe use in barrels of varyingdiameter.

It is a further object of the invention to provide a blow molded barrellinear adapted to be used in a tighthead drum and capable ofwithstanding a drop in a tighthead drum of four feet when filled withwater without breaking or leaking.

Yet another object of the present invention is to provide a drum linerhaving a plurality of longitudinally extending flutes formed in the sidewalls thereof.

A still further object of the present invention is to provide aflexible, unitary thermoplastic drum liner having closure receivingmeans integrally mounted therein.

These and other objects of this invention will become more apparent inthe following detailed discussion in which reference is made to theattached drawing which depicts an illustrative embodiment of the presentinvention.

In the drawing:

FIGURE 1 is a perspective view of a drum or barrel, partly broken awayto expose the liner contained therein, and

FIGURE 2 is a top plan view of the drum or barrel of FIGURE 1, partlybroken away to expose the liner. The terms drum and barrel are employedherein as equivalents and as used herein they are not intended to berestrictive, but to denominate any like containers.

A conventional drum or barrel is illustrated at 10 having a generallycylindrical side wall 12, although conventional encircling stiffeningconvolutions and other shapes may form an integral part of the sidewall. The generally cylindrical volume defined between the upper end 14and lower end 16 of the side wall 12 is enclosed by a disk-like top 18and a disk-like bottom 20, respectively. The peripheries of the topmember 18 and bottom member 20 are secured to the side wall ends 14 and16 as by crimping as at 22, lip rolling, welding or any conventionalmeans.

Disposed within the barrel or drum 10 is a unitary, seamless liner 24embodying principles of the present invention. The liner 24 ispreferably blow molded according to established techniques although itmay be desirable in some cases to form the liner 24 using other methods.The liner 24 is preferably composed of a somewhat flexible, moldablethermoplastic material such as polyethylene; polypropylene; irradiatedpolyethylene, i.e., irradiated to an extent of 2X10 rad. to 2O 10 rad.;polyvinyl chloride; Saran, e.g., vinylidene chlorideacrylonitrilecopolymer (:20) or vinylidene chloridevinyl chloride (:15); rubberhydrochloride; Dacron, e.g., polyethylene terephthalate; nylon, e.g.,polymeric hexamethylene adipamide; polymeric epsilon caprolactam;polyvinyl fluoride and like materials.

The liner 24 is characterizeed by having a plurality of flutes 26 formedin the generally cylindrical side wall 28 thereof which extendlongitudinally of the liner in a sub stantially parallel manner andmerge into integrally molded upper and lower liner ends 30 and 32 whichcorrespond in location on the liner 24 to the position of the ends 18and 20 on the barrel 10, thereby defining a closed cylindrical volume 34within the liner 24. Particularly if the liner 24 is blow molded it mayhave non-fluted side wall portions 36 which constitute a minor portionof the periphery of the liner side wall. As shown, the two diametricallyopposed non-fluted portions 36 conveniently provide for the separationof the halves of the mold employed in forming the liner 24. It should berealized that fiuting may be provided to a greater or lesser extentaround the side wall depending on the forming method employed and theamount of radial expansibility desired for the drum as discussedhereinbelow. In any case, the fluted portions 26 generally extend over amajor portion of the liner side wall 28.

Preferably a filling and removal opening 38 is formed in the liner top30, being defined by a generally hollow ingprotrudes through a suitableopening 44 formed in the drum or barrel which may be the conventionalbung hole of the barrel. The closure assembly for the barrel preferablyincludes means for retaining the neck 40 against accidental withdrawalinto the barrel; for instance, an as- :sembly such as that provided inthe commonly assigned Jcopending application Serial No. 276,807, filedApril 30,

1963, now Patent No. 3,167,210, granted January 26, 1965.

The liner 24 is preferably slidably urged longitudinally into the barrel'10 before the barrel top 18 has been put in position, thereafter thetop is conventionally secured in place as outlined above, to produce atight-head drum having an integral, seamless liner of somewhat flexible,relatively inert material.

As noted above, most liquid transportation drums are of the 55 gallonvariety; however, these drums do not all have the same physicaldimensions. In particular, it is Well known that the interior diametersof 55 gallon drums may be anywhere within the approximate range of 22 /2to 23 inches, the narrow drums being slightly longer so as to includethe same gallonage. For this reason it has not been readily possiblewith drum liners of the prior art, of other than the previouslymentioned coating variety, to form a smooth fit with any drum Whetherwide or narrow; This deficiency necessitated either being satisfied .toform a good fit with one diameter of drum and and a loose or pinched fitwith others or else providing prohibitively'costly duplication ofmolding or forming machinery to produce drum liners of various diameterscorresponding to the diameters of available drums of the particularvolumetric capacity.

In contradistinction to the obvious unattractiveness .of each of thesealternatives the drum liner provided by this invention is aptlydescribed as universal for barrels or drums at particular capacitybecause the fluting provided on the lining side walls allows the linerto radially expand to conform to the diameter of the particular drum inwhich it is employed. For instance, it has been found that a liner 24,embodying the invention, formed from polyethylene and having fluting of/8 inch peak-to-trough depth and t1 inch flute width coveringapproximately 80 percent of the periphery of the liner side wall andhaving an initial major diameter of 23 inches, was easily accommodat din a drum having a 22 /2 inch interior diameter. The liner was assembledto the drum by simply longitudinally sliding it into the drum beforesecuring the cover to the drum. Of course, where a substantial radialcontraction range is anticipated, means such as concentric fluting canbe provided in the top and bottom of the liners to absorb any tendencyof the top and bottom members to bow or wrinkle.

Where vibration during transportation is an especially important factor,generally radially extending fluting such as flutes 46 shown in FIGURE2, may be formed in the liner top 30. Experimentation has shown thatsufficient strengthening and rigidity for resistance to severe vibrationwill be imparted to a 55 gallon drum liner of the type disclosed hereinif fluting is formed in the liner top in the central areas between theparting line of the mold in which the radially extending flutes 46 aregenerally perpendicular to the parting line. The flutes 46 may beextensions of the vertical side wall flutes 26, as shown, or may beentirely independent therefrom. In the latter case, the flutes 46 shouldextend around the corner defined between the liner top 30 and'the sidewall 28 and should extend down the side wall at least far enough to passthe normal level that liquid will have in the drum duringtransportation. Particularly, when some or all of the flutes 46 extendindependently of the flutings 26 they may be made of differentconfiguration and depth than the flutes 26, for instance they may have adifferent spacing and be formed as deeper convolutions than the flutes26.

It has been found that, for a 55 gallon drum, two sets of 5 flutes 46diametrically opposed from one another on the liner top 30 and extending6 inc-hes down the liner side walls 28 independently of the flutes 26,in the area generally at right angles to the non-fluted parting linearea 36 where, in a blow molded liner the material tends to be somewhatthinner than at other areas, stiflens the liner and thereby increasesits resistance to vibration by several orders of magnitude. In additionthe flutes 46, which also aid in adapting the liners ,24 to drums ofslightly different heights, may be conveniently arranged on the linerbottom 32 in a like manner.

It should be noted that the ease with which a liner of the invention isplaced in a drum is provided in part by the fact that thermoplasticmaterial preferably composing the liner is somewhat self lubricating,and that the contact area between the liner side wall and the drum sidewall is minimized in that only the flute peaks and unfluted portionsengage the drum side walls. This last feature is additionally importantduring the assembling process because the ducts defined betweenadjoining flute peaks and the drum side wall allow air trapped betweenthe liner bottom and the drum bottom as the liner is being advanced intothe drum, to pass freely out of the drum rather than providingincreasing resistance to the positioning of the liner as would be thecase if the liner side Walls were smooth.

Additionally, it is easy to see that the longitudinally extending flutesor convolutions 26 strongly oppose any tendency of the liner to collapseeither longitudinally or radially because they act as ribs or columnslongitudinally While acting as radially outwardly biased resilient meansor springs in the radial'direction.

The seamlessness and rigidity of the liners provided by this invention,even though they are relatively thin walled, make them easily usablewith the preferred tight-head drum and hence provide lined drums able towithstand the water filled four foot drop test that enables tight-headdrums so lined to be used in interstate commerce.

It should be obvious that although the liner illustrated in the drawingas been included within a metallic drum, that liners embodying theprinciples of this invention may be used in fiber board and otherbarrels, dums and like containers and that the particular dimensionalconfiguration of flutes shown can be modified without departing from thepurview of this invention.

It should also be realized that other modifications may be made withrespect to the specific illustrative embodiment of the present inventionas shown,'without departing from the principles of this invention asclearly delineated herein and therefore the present invention embracesall modifications within the spirit and scope of the claims appendedhereto.

What is claimed is:

1. A radially expansible cylindrical drum liner formed of flexible inertstrong thermoplastic selected from the group consisting of polyethylene,polypropylene, irradiated polypropylene, polyvinylchloride, rubberhydrochloride, polyethylene terephthalate, polymeric hexamethyleneadipamide and polyvinylfluoride comprising a generally cylindrical sideWall having a first end and a second end; a disk like top integrallysecured by molding at the periphery thereof to said side wall first end;a disk like bottom integrally secured by molding at the peripherythereof to said side wall second end so as to include a generallycylindrical closed volume within said liner between said top and saidbottom; means defining a plurality of generally radially extendingconvolutions in the disk-like top of said liner; and fluting means insaid side wall defining a plurality of generally parallel,longitudinally extending convolutions located around a major part of theperiphery in said side wall, said fiuting means merging into theintegrally molded top and bottom, means defining an opening through theliner top, a tubular neck secured by molding as an integral extension ofsaid top to form a seamless entity of said liner, said tubular neckextending outwardly of said top surrounding said opening, said linerbeing adapted to be inserted into a drum of slightly smaller diameterwhen the liner is unconfined so that the longitudinally directed flutesare resiliently urged into intimate contact with the drum side Wallinterior thereby eliminating abrasion damage when the loaded drum andliner are shifted, and radially extending flutes at one end of saidliner located centrally and alongside of the nonfluted areas of the sidewall.

2. The combination comprising a generally cylindrical drum including agenerally cylindrical side wall, and a disk like top and a disk likebottom secured to opposite ends of said side wall as to define a closed,generally cylindrical volume within the drum between said bottom andsaid top; and a generally cylindrical radially expansible drum linerformed of flexible strong inert thermoplastic selected from the groupconsisting of polyethylene, polypropylene, irradiated polypropylene,polyvinylchloride, rubber hydrochloride, polyethylene terephthalate,polymeric hexamethylene adipamide and polyvinylfluoride within saidbarrel, said drum liner comprising a unitary blow-molded top, bottom andside walls, a tubular neck integrally secured to said top whichsurrounds said top and is an extension of a sleeveless entity therewith,said liner walls defining a generally cylindrically closed volumebetween top and bottom and defining fluting means in the form of aplurality of generally parallel longitudinally extending convolutionslocated around a major part of the periphery in said liner walls leavinga non-fluted central zone therein, said convolutions resiliently engagesaid drum side wall as to prevent substantial vibration of said linerwith respect to the drum during shipping of said drum, and radiallyextending flutes at one end of said liner located centrally andalongside of the non-fluted areas of the side wall.

References Cited by the Examiner UNITED STATES PATENTS 2,861,714 11/58Glossop 22063 2,873,782 2/59 Gunn -5 3,027,044 3/62 Winstead 220-723,135,420 6/64 Farell et al. 22063 FOREIGN PATENTS 1,13 2,494 6/ 62Germany.

THERON E. CONDON, Primary Examiner.

EARLE J. DRUMMOND, Examiner.

1. A RADIALLY EXPANSIBLE CYLINDRICAL DRUM LINER FORMED OF FLEXIBLE INERTSTRONG THERMOPLASTIC SELECTED FROM THE GROUP CONSISTING OF POLYETHYLENE,POLYPROPYLENE, IRRADIATED POLYPROPYLENE, POLYVINYLCHLORIDE, RUBBERHYDROCHLORIDE, POLYETHYLENE TEREPHTHALATE, POLYMERIC HEXAMETHYLENEADIPAMIDE AND POLYVINYLFLUORIDE COMPRISING A GENERALLY CYLINDRICAL SIDEWALL HAVING A FIRST END AND A SECOND END; A DISK LIKE TOP INTEGRALLYSECURED BY MOLDING AT THE PERIPHERY THEREOF OF SAID SIDE WALL FIRST END;A DISK LIKE BOTTOM INTEGRALLY SECURED BY MOLDING AT THE PERIPHERYTHEREOF TO SAID SIDE WALL SECOND END SO AS TO INCLUDE A GENERALLYCYLINDRICAL CLOSED VOLUME WITHIN SAID LINER BETWEEN SAID TOP AND SAIDBOTTOM; MEANS DEFINING A PLURALITY OF GENERALLY RADIALLY EXTENDINGCONVOLUTIONS IN THE DISK-LIKE TOP OF SAID LINER; AND FLUTING MEANS INSAID SIDE WALL DEFINING A PLURALITY OF GENERALLY PARALLEL,LONGITUDINALLY EXTENDING CONVOLUTIONS LOCATED AROUND A MAJOR PART OF THEPERIPHERY IN SAID SIDE WALL, SAID FLUTING MEANS MERGING INTO THEINTEGRALLY MOLDED TOP AND BOTTOM, MEANS DEFINING AN OPENING THROUGH THELINER TOP, A TUBULAR NECK SECURED BY MOLDING AS AN INTEGRAL EXTENSION OFSAID TOP TO FORM A SEAMLESS ENTITY OF SAID LINER, SAID TUBULAR NECKEXTENDING OUTWARDLY OF SAID TOP SURROUNDING SAID OPENING, SAID LINERBEING ADAPTED TO BE INSERTED INTO A DRUM OF SLIGHTLY SMALLER DIAMETERWHEN THE LINER IS UNCONFINED SO THAT THE LONGITUDINALLY DIRECTED FLUTESARE RESILIENTLY URGED INTO INTIMATE CONTACT WITH THE DRUM SIDE WALLINTERIOR THEREBY ELIMINATING ABRASION DAMAGE WHEN THE LOADED DRUM ANDLINER ARE SHIFTED, AND RADIALLY EXTENDING FLUTES AT ONE END OF SAIDLINER LOCATED CENTRALLY AND ALONGSIDE OF THE NONFLUTED AREAS OF THE SIDEWALL.